1. Choose Tools > Administration > Project Options.
The Project Options dialog box opens.
2. Select the Requirement Documents category.
3. Select any Defer Requirement Document Numbering options.
Select a check box to automatically assign document numbers for the corresponding option. If you do not automatically assign numbers, you can manually assign numbers at a later time.
4. Enter the Next requirement document number.
The value must be greater than the largest existing document number.
5. Click OK to save the project options.